We have a system of equations
[tex]\begin{gathered} 6x+5y=300 \\ 3x+7y=285 \end{gathered}[/tex]we will multiply -2 the second equations
[tex]-6x-14y=-570[/tex]we sum the first equation and the equation above
[tex]\begin{gathered} -9y=-270 \\ y=\frac{-270}{-9} \\ y=30 \end{gathered}[/tex]the cost for each chocolate g
